The terminal tissue attachment and repair device generally relates to orthopedic devices and more specifically to an elongated tissue enwrapping and repair device. More particularly, the invention wraps one end of an elongated tissue and secures that end to a bony insertion or fixed anatomic point.
Effective repair of elongated tissue, such as flexor tendons, extensor tendons, ligaments, muscles and the like, has long been a significant problem that remains unresolved within the realms of hand surgery, orthopedic surgery and reconstructive musculoskeletal surgery. The pursuit of a secure, relatively simple, inexpensive surgical technique and device to assist and facilitate the effective repair of tendons, ligaments and other elongated tissues, still eludes hand surgeons, orthopedic surgeons and the practice and advancement of musculoskeletal reconstructive surgery.
The problems which must be addressed in any tendon, ligament or elongated soft tissue repair technique and device include creation of a connection, co-aptation or union of the cut end(s) of the tendon or ligament to each other in the case of a mid-substance disruption or to the distal bony attachment in the case of a terminal tendon disruption. Though this specification refers often to tendons and flexor tendon, the invention may see use upon ligaments, muscles, nerve tissue, and the like.
Flexor tendons in the hands and feet pass through a relatively narrow “tunnel” of fibro-osseus tissue which extends from the metacarpophalangeal, or MP joint proximally to the distal interphalangeal, or DIP joint distally. Tendon movement through this tunnel is referred to as “tendon excursion”. In the hand this region is known as “no man's land” and/or “zone 2” by orthopedic practitioners.
The term “no man's land” arose from early surgeons who indicated that primary repair of flexor tendons in this region of the hand could not be performed successfully. This pessimistic approach came about because the practitioners' experience of the repairs in this zone consistently failed due to adhesions and/or tendon rupture after repair. Because the results with primary flexor tendon repair were so dismal, hand surgeons avoided primary tendon repair and instead performed delayed secondary repairs with tendon grafting or performed no repairs of flexor tendons in this area at all.
When the tendon, ligament or elongated soft tissue is cut in its midsubstance and repair is performed, the two cut ends of the divided tissue are coapted, that is, held together and secured in this position using sutures or other tendon/ligament repair device. An end to end coaptation requires that enough tissue is available on either side of the laceration or rupture to facilitate “capture” and “purchase” of both ends of the ruptured soft tissue and securement with suture or other restraining material so that a secure union or coaptation between these two ends is established. Practitioners refer to this as an “end to end” repair of tendon, ligament or muscle. In connecting the two ends, this typically involves passing sutures through both sides of the lacerated tendon and then tying the two free ends of the suture together, thereby reapproximating and holding the cut ends together. Various suturing techniques have been used including a variety of crisscross patterns, looped sutures, locking sutures, and the like. A proper tendon repair must create a repair and connection between the two cut ends of the tendon strong enough to withstand the forces involved in muscle contraction, such as for finger, wrist, elbow, shoulder, knee or ankle movement. Many of the existing repair techniques for the treatment of tendon injuries involve the use of four, six, or eight suture strands which are passed through the tendon “core” to provide adequate purchase and “strength of repair.” Because multiple strands of suture pass through the “core” of the tendon, this also brings about multiple knots to secure the sutures which are holding the cut tendon ends together. These suture knots, may be placed in between the two cut ends at the site of the coaptation or on the outside of the tendon, depending on the technique utilized. When the knots are placed between the two cut ends at the site of the coaptation, the “core” sutures and knots may actually serve to prevent direct contact between the two ends of the healing tissue and this separation may serve to impede the tendon's ability to heal and form a stable repair/union.
When tendons are repaired utilizing current techniques the repaired tendon and adjacent joints must be immobilized afterwards so that the repair can heal. As a result of the prolonged period of immobilization required after repair, adhesions invariably form between the repaired tendon and the surrounding tissue. When tendon adhesions occur, then “excursion,” or movement of the repaired flexor tendon as it passes through the retinacular “pulley” system has significant inhibition or restriction. In repair techniques where the suture knots are placed on the outside of the repaired tendons, these knots may contact and catch on the fibrous pulleys of the retinacular system that surround the tendons, thereby impeding tendon excursion and joint motion. Knots on the outside of the tendon frequently become a source of irritation and adhesions often form between the suture knots and the surrounding soft tissues which limits tendon excursion and active motion of the affected joints.
When a tendon, ligament or musculo-tendinous unit is cut near a terminal end, either proximally near the origin or distally near the insertion, then there is typically not enough tissue on one side of the rupture to facilitate an “end to end” repair and the surgeon must repair a “terminal” end of a tendon or ligament back to bone or other fixed skeletal tissue. To accomplish this, the surgeon must capture the cut “terminal” end of the ruptured/lacerated tendon/soft tissue and then secure it to bone or other fixed skeletal tissues such as joint capsule. In previous techniques and previous art suture or other material is passed or woven through the midsubstance or “core” of the ruptured/lacerated soft tissue and then the free “distal” end or ends of the suture material (which has been passed through and emerges from the terminal end of the lacerated soft tissue) is then sutured together, attached to or passed through a bone tunnel and fixed to the bone, using a variety of “anchoring” techniques including simple sutures, bone anchors, interference screws, or buttons (external buttons outside the skin or internal, “endo” buttons).
As noted above, patients require a structurally sound and strong repair but at the same time, a repaired tendon must also be able to move relative to adjacent skeletal components (tendon excursion) early in the postoperative period in order to minimize adhesions and facilitate skeletal and/or joint movement an ultimate function.
Tendons move through anatomic “tunnels” of synovial tissue and/or through fibro osseous retinacular systems. Tendon movement through these areas is termed “tendon excursion.” Medicine has learned that the sooner active movement of the repaired tendon begins after the repair, the better, as long as this movement does not weaken or compromise the repair. Unfortunately, when early active motion is attempted after using current techniques, this movement results and gapping occurs at the repair site which can lead to tendon rupture.
Movement and excursion of a repaired or tendon serves to prevent and/or minimize adhesions between the repaired tendon and the surrounding tissues and thereby maximizing tendon excursion and optimizing skeletal movement. Similar to the problems encountered with suture material interfering with movement and/or healing of an “end to end” tendon repair, the same problems may occur with a “terminal tendon repair” when the suture material physically interferes with healing between the tendons and bone and/or results in adhesions between the tendon and surrounding soft tissues, thereby compromising healing and/or joint motion.
While the strength of the repair may be addressed by utilization of stronger and more numerous suture strands, the prior art has overlooked the bulkiness of the repaired sutured tendon at the site of the coaptation. The prior art does not adequately address the essential need to reproduce the normal anatomic shape of tendon at the repair site. An anatomic shape of the tendon at the site of the repair minimizes friction, facilitating the passage of the repaired tendon through the adjacent soft tissue, thereby maximizing tendon excursion. The bulkiness at the repair site comes from fraying of the lacerated tendon ends, hydration and swelling of the cut ends after an injury, from knots on or within the repaired tendon, and secondary to bunching of the two tendon ends brought together, all of which prevent movement and excursion of the repaired flexor tendon and compromise the ultimate functional results. Multiple sutures and knots at the repair site, as well as the “accordion effect” associated with tendon re-approximation site all contribute to the “fat repair site” which severely limits excursion and ultimately results in a poor functional result. Tendon re-approximation or coaptation occurs where the two cut ends are drawn together so that the tendon ends are compressed longitudinally and “bunched.” The end result is a bulky repair site where the repaired tendon has a significantly larger diameter than the normal anatomic state, and a more irregular non-anatomic shape than the natural tendon. This bulkiness at the repair site and the non-anatomic shape of the repaired tendon has a profound negative effect on the ability of the repaired flexor tendon to move through the flexor tendon retinaculum system. Decreased friction and increased excursion at the repair site will serve minimize stress forces on the repair construct thereby protecting the repair, enhancing blood flow and healing at the repair site and decreasing the chances of adhesions or disruption at the repair site.
Medicine has the goal of developing a device or technique for repair of tendon, ligament or elongated anatomic tissue which is strong enough to withstand early, or immediate, active movement of the tendon, finger, hand, wrist, elbow, knee. ankle or involved joint/extremity after the repair. When early active motion begins very soon after the repair, then the risk of tendon adhesions reduces significantly. However, as noted above, early active motion requires a strong repair to resist gapping and minimum friction between the repaired tissue at the site of the repair and the surrounding soft tissue, synovial tissue, fibro-osseous tunnel and/or retinacular pulley system, through which the repaired tendon must pass.
The repair technique must ideally reproduce the normal anatomic size and shape of the uninjured tendon at the site of the tendon coaptation. Frequently, excessive bulkiness at the repair site occurs due to poor repair technique, excessive suture material and bunching of the repaired tissue at the repair site due to the “accordion effect”. Reproducing the normal anatomic size and shape of the tendon at the repair site by decreasing excessive bulkiness of the soft tendon repair will help prevent the tendon from getting “hung up,” or adherent to the surrounding soft tissue, through which the tendon must pass.
The ideal tendon repair construct accomplishes these goals: 1) enough strength and structural integrity to withstand the forces of muscle contraction, preventing gapping at the repair site and allowing for early active motion immediately after the repair; 2) optimize healing, blood flow and vascularity between the repaired/reapproximated cut tendon ends (end to end repair) or between the tendon and bone (terminal tendon repair); and 3) reproduce or approximate the normal anatomic shape of the tendon at the repair interface which will minimize friction and allow for normal unimpeded tendon excursion through the retinacular tunnel and/or surrounding soft tissues which will also help facilitate immediate active motion after repair.
The ideal tendon repair construct would securely fix the ruptured tendon ends together (end to end repair) or tendon to bone (terminal tendon repair). The ideal repair construct must also optimize healing and vascularity/blood flow at the repair site, re-create normal anatomy, minimize friction and adhesions at the repair site and allow for active skeletal motion to begin immediately after the repair.